A few months before I was born, two previously undefeated boxers, Muhammad Ali (31-0)and Joe Frazier (26-0) fought for the heavyweight title in the so-called “Fight of the Century” at Madison Square Garden. That was forty years ago today. It was not their greatest fight–that would be the Thrilla in Manila–but it was possibly the biggest spectacle in boxing history.

The two of them had been friends before their violent Garden party. When Ali was stripped of his heavyweight championship in 1967 for refusing induction into the military and found himself wandering the college lecture circuit, Frazier loaned him money. It was a fitting gesture, for Frazier now wore the crown that had been Ali’s. But he vowed he would give the deposed champ a chance to win it back, and when Ali was allowed to return to the ring in 1970, Frazier did something that isn’t standard practice in the cutthroat world of boxing. He kept his word.

They would each make $2.5 million and fight in front of a Garden crowd that overflowed with celebrities. Burt Lancaster, Sinatra’s co-star in From Here to Eternity, did the radio commentary. But the only thing that really mattered was the hatred that had erupted when Ali called Frazier an Uncle Tom and a tool of good-old-boy sheriffs and Ku Klux Klansmen. In a lifetime filled with kindness as well as greatness, it was a low moment for Ali. He knew full well that Frazier, the thirteenth child born to a one-armed North Carolina sharecropper, had traveled a far harder road than he had. By comparison, Ali was a child of privilege, raised in relative comfort in Louisville, his boxing career bankrolled by local white businessmen. But he got away with it because he was handsome, charming, funny, all the things Frazier was not.

Ali was the first in the ring, in a red velvet robe with matching trunks, and white shoes with red tassels. He glided in a circle to a crush of sound, a strand of blown grass. Whatever you might have thought of him then, you were forced to look at him with honest, lingering eyes, for there might never be his like again. Assessed by ring demands–punch, size, speed, intelligence, command, and imagination–he was an action poet, the equal of the best painting you could find or a Mozart who failed to die too early. If that is an overstatement, disfiguring the finer arts by association with a brute game, consider the mudslide of purple that attaches to his creative lessers in other fields, past and present; Ali was physical art, belonged alone in a museum of his own. I was extremely fond of him, of his work, of the decent side of his nature, and jaundiced on his cultish servility, his termopolitical combustions that tried to twist adversaries into grotesque shapes. It never worked, excerpt perhaps on Liston, who came to think that he was clinically insane. It did work on himself, shaped the fear for his face and general well-being into a positive force, a psychological war dance that blew up the dam and released his flood of talent. The trouble was that, like Kandinsky’s doubled-sided painting of chaos and calm, it became increasingly difficult for him to find his way back from one side to the other.

In a green and gold brocade robe with matching trunks, Joe Frazier almost seemed insectile next to Ali in the ring, and he was made more so as Ali waltzed by him, bumped him and said: “Chum!” Far from that slur, Joe was a gladiator right smack to the root conjurings of the title, to the clank of armor he seemed to emit. Work within his perimeter, and you courted what fighters used to call “the black spot,” the flash knockout. He was a figher that could be hit with abandon, but if you didn’t get him out of there his drilling aggression, his marked taste for pursuit and threshing-blade punches could overwhelm you; as one military enthusiast in his camp siad, “like the Wehrmacht crossing into Russia.” I was drawn to the honesty of his work, the joy he derived from inexorable assault, yet had a cool neutrality to his presence. In truth, with a jewel in each hand, i didn’t want to part with either of them, thus making me pitifully objective, a captial sinner in the most subjective and impressionistic of all athletic conflicts.

Frazier won the fight, of course, in front of a celebrity-studded crowd. Dali, Elvis, Woody and the Beatles were there. Burt Lancaster did the color for the closed-circut broadcast and Frank Sinatra was there taking pictures for Life Magazine.

While it promised sufficient sporting spectacle and mystery (could Ali reclaim the grace of his youth and now, nearing 30, reclaim the title that many thought was still rightfully his?), the fight also operated as a social ballot box. Ali, who’d been a sort of political prisoner, commanded the support of every freethinker in the country and beyond, striking his revolutionary stance. In addition, he somehow cast a fight between two black men as a racial referendum, a puzzled and comically outraged Frazier now a stand-in for the status quo and the white man as well.

All this was accomplished with the primitive promotional platforms at hand: newspapers, radio and talk shows. The intrigue was still enough to make the fight the hottest ticket of a lifetime, possibly the most glamour-struck event ever. The excitement was overwhelming, even far beyond the Garden, but can you imagine what it might have been like if Ali, the ultimate pitchman, had, say, a Facebook page? If we’re so eager to exploit celebrity that a semifamous athlete like Chad Ochocinco has his own reality show, then you can be certain Ali would have had his own network long before Oprah.

Then again, how could our digital applications improve upon the analog beauty of their struggles that night, an eye-popping brutality that Frazier narrowly won, a contest of such evenly matched wills, such equal desperation that the words Ali-Frazier have come to signify a kind of ruinous self-sacrifice? The old ways are not necessarily the best, but once a generation, anyway, they’re good enough.

He has known for years of Frazier’s anger and bitterness toward him, but he knows nothing of the venom that coursed through Frazier’s recent autobiography, Smokin’ Joe. Of Ali, Frazier wrote, “Truth is, I’d like to rumble with that sucker again—beat him up piece by piece and mail him back to Jesus…. Now people ask me if I feel bad for him, now that things aren’t going so well for him. Nope. I don’t. Fact is, I don’t give a damn. They want me to love him, but I’ll open up the graveyard and bury his ass when the Lord chooses to take him.”

Nor does Ali know what Frazier said after watching him, with his trembling arm, light the Olympic flame: “It would have been a good thing if he would have lit the torch and fallen in. If I had the chance, I would have pushed him in.”

Nor does Ali know of Frazier’s rambling diatribe against him at a July 30 press conference in Atlanta, where Frazier attacked the choice of Ali, the Olympic light heavyweight gold medalist in 1960 and a three-time heavyweight champion of the world, as the final bearer of the torch. He called Ali a “dodge drafter,” implied that Ali was a racist (“He didn’t like his white brothers,” said Frazier) and suggested that he himself—also an Olympic champion, as a heavyweight, in 1964—would have made a better choice to light the flame: “Why not? I’m a good American…. A champion is more than making noise. I could have run up there. I’m in shape.”

And while Frazier asserts at one turn that he sees “the hand of the Lord” in Ali’s Parkinson’s syndrome (a set of symptoms that include tremors and a masklike face), he also takes an eerily mean-spirited pride in the role he believes he played in causing Ali’s condition. Indeed, the Parkinson’s most likely traces to the repealed blows Ali took to the head as a boxer—traumas that ravaged the colony of dopamine-producing cells in his brain—and no man struck Ali’s head harder and more repeatedly than Frazier.

“He’s got Joe Frazier-itis,” Frazier said of Ali one day recently, flexing his left arm. “He’s got left-hook-itis.”

Check out this cool photo gallery of “The Fight of the Century” over at Life.com.